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	<optgroup label="Properties">
		
		<option value="//api/name/calculatedLayout">calculatedLayout</option>
		
		<option value="//api/name/contentsScaleForDisplay">contentsScaleForDisplay</option>
		
		<option value="//api/name/inHierarchy">inHierarchy</option>
		
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	<optgroup label="Class Methods">
		
		<option value="//api/name/displayWithParameters:isCancelled:">+ displayWithParameters:isCancelled:</option>
		
		<option value="//api/name/drawRect:withParameters:isCancelled:isRasterizing:">+ drawRect:withParameters:isCancelled:isRasterizing:</option>
		
	</optgroup>
	

	
	<optgroup label="Instance Methods">
		
		<option value="//api/name/asyncTraitCollectionDidChange">- asyncTraitCollectionDidChange</option>
		
		<option value="//api/name/calculateLayoutThatFits:">- calculateLayoutThatFits:</option>
		
		<option value="//api/name/calculateLayoutThatFits:restrictedToSize:relativeToParentSize:">- calculateLayoutThatFits:restrictedToSize:relativeToParentSize:</option>
		
		<option value="//api/name/calculateSizeThatFits:">- calculateSizeThatFits:</option>
		
		<option value="//api/name/calculatedLayoutDidChange">- calculatedLayoutDidChange</option>
		
		<option value="//api/name/clearContents">- clearContents</option>
		
		<option value="//api/name/clearFetchedData">- clearFetchedData</option>
		
		<option value="//api/name/descriptionForRecursiveDescription">- descriptionForRecursiveDescription</option>
		
		<option value="//api/name/didEnterDisplayState">- didEnterDisplayState</option>
		
		<option value="//api/name/didEnterPreloadState">- didEnterPreloadState</option>
		
		<option value="//api/name/didEnterVisibleState">- didEnterVisibleState</option>
		
		<option value="//api/name/didExitDisplayState">- didExitDisplayState</option>
		
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		<option value="//api/name/didLoad">- didLoad</option>
		
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		<option value="//api/name/gestureRecognizerShouldBegin:">- gestureRecognizerShouldBegin:</option>
		
		<option value="//api/name/hitTest:withEvent:">- hitTest:withEvent:</option>
		
		<option value="//api/name/interfaceStateDidChange:fromState:">- interfaceStateDidChange:fromState:</option>
		
		<option value="//api/name/invalidateCalculatedLayout">- invalidateCalculatedLayout</option>
		
		<option value="//api/name/layout">- layout</option>
		
		<option value="//api/name/layoutDidFinish">- layoutDidFinish</option>
		
		<option value="//api/name/layoutSpecThatFits:">- layoutSpecThatFits:</option>
		
		<option value="//api/name/placeholderImage">- placeholderImage</option>
		
		<option value="//api/name/recursivelySetNeedsDisplayAtScale:">- recursivelySetNeedsDisplayAtScale:</option>
		
		<option value="//api/name/setNeedsDisplayAtScale:">- setNeedsDisplayAtScale:</option>
		
		<option value="//api/name/subnodeDisplayDidFinish:">- subnodeDisplayDidFinish:</option>
		
		<option value="//api/name/subnodeDisplayWillStart:">- subnodeDisplayWillStart:</option>
		
		<option value="//api/name/touchesBegan:withEvent:">- touchesBegan:withEvent:</option>
		
		<option value="//api/name/touchesCancelled:withEvent:">- touchesCancelled:withEvent:</option>
		
		<option value="//api/name/touchesEnded:withEvent:">- touchesEnded:withEvent:</option>
		
		<option value="//api/name/touchesMoved:withEvent:">- touchesMoved:withEvent:</option>
		
		<option value="//api/name/willEnterHierarchy">- willEnterHierarchy</option>
		
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					<h1 class="title">ASDisplayNode(Subclassing) Category Reference</h1>

					
					<div class="section section-specification"><table cellspacing="0"><tbody>
						<tr>
	<th>Declared in</th>
	<td>ASDisplayNode+Subclasses.h</td>
</tr>
						</tbody></table></div>
					

                    
					
					<div class="section section-overview">
						<a title="Overview" name="overview"></a>
						<h2 class="subtitle subtitle-overview">Overview</h2>
						<p>The subclass header <em>ASDisplayNode+Subclasses</em> defines the following methods that either must or can be overriden by
subclasses of ASDisplayNode.</p>

<p>These methods should never be called directly by other classes.</p>

<h2>Drawing</h2>

<p>Implement one of +displayWithParameters:isCancelled: or +drawRect:withParameters:isCancelled: to provide
drawing for your node.</p>

<p>Use -drawParametersForAsyncLayer: to copy any properties that are involved in drawing into an immutable object for
use on the display queue. The display and drawRect implementations <em>MUST</em> be thread-safe, as they can be called on
the displayQueue (asynchronously) or the main thread (synchronously/displayImmediately).</p>

<p>Class methods that require passing in copies of the values are used to minimize the need for locking around instance
variable access, and the possibility of the asynchronous display pass grabbing an inconsistent state across multiple
variables.</p>
					</div>
					
					

					
					
					<div class="section section-tasks">
						<a title="Tasks" name="tasks"></a>
						

						<a title="Properties" name="task_Properties"></a>
						<h2 class="task-title">Properties</h2>

						<div class="task-list">
							<div class="section-method">
	<a name="//api/name/calculatedLayout" title="calculatedLayout"></a>
	<h3 class="method-title"><code><a href="#//api/name/calculatedLayout">&nbsp;&nbsp;calculatedLayout</a></code>
</h3>

	<div class="method-info">
		<div class="pointy-thing"></div>

		<div class="method-info-container">
			
			
			<div class="method-subsection brief-description">
				<p>Return the calculated layout.</p>
			</div>
			
		    

			<div class="method-subsection method-declaration"><code>@property (nullable, nonatomic, readonly, assign) ASLayout *calculatedLayout</code></div>

		    
			

			
			<div class="method-subsection return">
				<h4 class="method-subtitle parameter-title">Return Value</h4>
				<p>Layout that wraps calculated size returned by -calculateSizeThatFits: (in manual layout mode),
or layout already calculated from layout spec returned by -layoutSpecThatFits: (in automatic layout mode).</p>
			</div>
			

			

			
			<div class="method-subsection discussion-section">
				<h4 class="method-subtitle">Discussion</h4>
				<p>For node subclasses that implement manual layout (e.g., they have a custom -layout method),
calculatedLayout may be accessed on subnodes to retrieved cached information about their size.
This allows -layout to be very fast, saving time on the main thread.
Note: .calculatedLayout will only be set for nodes that have had -measure: called on them.
For manual layout, make sure you call -measure: in your implementation of -calculateSizeThatFits:.</p>

<p>For node subclasses that use automatic layout (e.g., they implement -layoutSpecThatFits:),
it is typically not necessary to use .calculatedLayout at any point.  For these nodes,
the ASLayoutSpec implementation will automatically call -measureWithSizeRange: on all of the subnodes,
and the ASDisplayNode base class implementation of -layout will automatically make use of .calculatedLayout on the subnodes.</p><div class="warning"><p><strong>Warning:</strong> Subclasses must not override this; it returns the last cached layout and is never expensive.</p></div>
			</div>
			

			

			

			
			<div class="method-subsection declared-in-section">
				<h4 class="method-subtitle">Declared In</h4>
				<p><code class="declared-in-ref">ASDisplayNode+Subclasses.h</code></p>
			</div>
			
			
		</div>
	</div>
</div>
						</div>
						

						<a title="View Lifecycle" name="task_View Lifecycle"></a>
						<h2 class="task-title">View Lifecycle</h2>

						<div class="task-list">
							<div class="section-method">
	<a name="//api/name/didLoad" title="didLoad"></a>
	<h3 class="method-title"><code><a href="#//api/name/didLoad">&ndash;&nbsp;didLoad</a></code>
</h3>

	<div class="method-info">
		<div class="pointy-thing"></div>

		<div class="method-info-container">
			
			
			<div class="method-subsection brief-description">
				<p>Called on the main thread immediately after self.view is created.</p>
			</div>
			
		    

			<div class="method-subsection method-declaration"><code>- (void)didLoad</code></div>

		    
			

			

			

			
			<div class="method-subsection discussion-section">
				<h4 class="method-subtitle">Discussion</h4>
				<p>This is the best time to add gesture recognizers to the view.</p>
			</div>
			

			

			

			
			<div class="method-subsection declared-in-section">
				<h4 class="method-subtitle">Declared In</h4>
				<p><code class="declared-in-ref">ASDisplayNode+Subclasses.h</code></p>
			</div>
			
			
		</div>
	</div>
</div>
						</div>
						

						<a title="Layout" name="task_Layout"></a>
						<h2 class="task-title">Layout</h2>

						<div class="task-list">
							<div class="section-method">
	<a name="//api/name/layout" title="layout"></a>
	<h3 class="method-title"><code><a href="#//api/name/layout">&ndash;&nbsp;layout</a></code>
</h3>

	<div class="method-info">
		<div class="pointy-thing"></div>

		<div class="method-info-container">
			
			
			<div class="method-subsection brief-description">
				<p>Called on the main thread by the view&rsquo;s -layoutSubviews.</p>
			</div>
			
		    

			<div class="method-subsection method-declaration"><code>- (void)layout</code></div>

		    
			

			

			

			
			<div class="method-subsection discussion-section">
				<h4 class="method-subtitle">Discussion</h4>
				<p>Subclasses override this method to layout all subnodes or subviews.</p>
			</div>
			

			

			

			
			<div class="method-subsection declared-in-section">
				<h4 class="method-subtitle">Declared In</h4>
				<p><code class="declared-in-ref">ASDisplayNode+Subclasses.h</code></p>
			</div>
			
			
		</div>
	</div>
</div><div class="section-method">
	<a name="//api/name/layoutDidFinish" title="layoutDidFinish"></a>
	<h3 class="method-title"><code><a href="#//api/name/layoutDidFinish">&ndash;&nbsp;layoutDidFinish</a></code>
</h3>

	<div class="method-info">
		<div class="pointy-thing"></div>

		<div class="method-info-container">
			
			
			<div class="method-subsection brief-description">
				<p>Called on the main thread by the view&rsquo;s -layoutSubviews, after -layout.</p>
			</div>
			
		    

			<div class="method-subsection method-declaration"><code>- (void)layoutDidFinish</code></div>

		    
			

			

			

			
			<div class="method-subsection discussion-section">
				<h4 class="method-subtitle">Discussion</h4>
				<p>Gives a chance for subclasses to perform actions after the subclass and superclass have finished laying
out.</p>
			</div>
			

			

			

			
			<div class="method-subsection declared-in-section">
				<h4 class="method-subtitle">Declared In</h4>
				<p><code class="declared-in-ref">ASDisplayNode+Subclasses.h</code></p>
			</div>
			
			
		</div>
	</div>
</div><div class="section-method">
	<a name="//api/name/calculatedLayoutDidChange" title="calculatedLayoutDidChange"></a>
	<h3 class="method-title"><code><a href="#//api/name/calculatedLayoutDidChange">&ndash;&nbsp;calculatedLayoutDidChange</a></code>
</h3>

	<div class="method-info">
		<div class="pointy-thing"></div>

		<div class="method-info-container">
			
			
			<div class="method-subsection brief-description">
				<p>Called on a background thread if !isNodeLoaded - called on the main thread if isNodeLoaded.</p>
			</div>
			
		    

			<div class="method-subsection method-declaration"><code>- (void)calculatedLayoutDidChange</code></div>

		    
			

			

			

			
			<div class="method-subsection discussion-section">
				<h4 class="method-subtitle">Discussion</h4>
				<p>When the .calculatedLayout property is set to a new ASLayout (directly from -calculateLayoutThatFits: or
calculated via use of -layoutSpecThatFits:), subclasses may inspect it here.</p>
			</div>
			

			

			

			
			<div class="method-subsection declared-in-section">
				<h4 class="method-subtitle">Declared In</h4>
				<p><code class="declared-in-ref">ASDisplayNode+Subclasses.h</code></p>
			</div>
			
			
		</div>
	</div>
</div>
						</div>
						

						<a title="Layout calculation" name="task_Layout calculation"></a>
						<h2 class="task-title">Layout calculation</h2>

						<div class="task-list">
							<div class="section-method">
	<a name="//api/name/calculateLayoutThatFits:" title="calculateLayoutThatFits:"></a>
	<h3 class="method-title"><code><a href="#//api/name/calculateLayoutThatFits:">&ndash;&nbsp;calculateLayoutThatFits:</a></code>
</h3>

	<div class="method-info">
		<div class="pointy-thing"></div>

		<div class="method-info-container">
			
			
			<div class="method-subsection brief-description">
				<p>Calculate a layout based on given size range.</p>
			</div>
			
		    

			<div class="method-subsection method-declaration"><code>- (ASLayout *)calculateLayoutThatFits:(ASSizeRange)<em>constrainedSize</em></code></div>

		    
			
			<div class="method-subsection arguments-section parameters">
				<h4 class="method-subtitle parameter-title">Parameters</h4>
				<table class="argument-def parameter-def">
				
					<tr>
						<th scope="row" class="argument-name"><code>constrainedSize</code></th>
						<td><p>The minimum and maximum sizes the receiver should fit in.</p></td>
					</tr>
				
				</table>
			</div>
			

			
			<div class="method-subsection return">
				<h4 class="method-subtitle parameter-title">Return Value</h4>
				<p>An ASLayout instance defining the layout of the receiver (and its children, if the box layout model is used).</p>
			</div>
			

			

			
			<div class="method-subsection discussion-section">
				<h4 class="method-subtitle">Discussion</h4>
				<p>This method is called on a non-main thread. The default implementation calls either -layoutSpecThatFits:
or -calculateSizeThatFits:, whichever method is overriden. Subclasses rarely need to override this method,
override -layoutSpecThatFits: or -calculateSizeThatFits: instead.</p><div class="note"><p><strong>Note:</strong> This method should not be called directly outside of ASDisplayNode; use -measure: or -calculatedLayout instead.</p></div>
			</div>
			

			

			

			
			<div class="method-subsection declared-in-section">
				<h4 class="method-subtitle">Declared In</h4>
				<p><code class="declared-in-ref">ASDisplayNode+Subclasses.h</code></p>
			</div>
			
			
		</div>
	</div>
</div><div class="section-method">
	<a name="//api/name/calculateLayoutThatFits:restrictedToSize:relativeToParentSize:" title="calculateLayoutThatFits:restrictedToSize:relativeToParentSize:"></a>
	<h3 class="method-title"><code><a href="#//api/name/calculateLayoutThatFits:restrictedToSize:relativeToParentSize:">&ndash;&nbsp;calculateLayoutThatFits:restrictedToSize:relativeToParentSize:</a></code>
</h3>

	<div class="method-info">
		<div class="pointy-thing"></div>

		<div class="method-info-container">
			
			
			<div class="method-subsection brief-description">
				<p>ASDisplayNode&rsquo;s implementation of -layoutThatFits:parentSize: calls this method to resolve the node&rsquo;s size
against parentSize, intersect it with constrainedSize, and call -calculateLayoutThatFits: with the result.</p>
			</div>
			
		    

			<div class="method-subsection method-declaration"><code>- (ASLayout *)calculateLayoutThatFits:(ASSizeRange)<em>constrainedSize</em> restrictedToSize:(ASLayoutElementSize)<em>size</em> relativeToParentSize:(CGSize)<em>parentSize</em></code></div>

		    
			

			

			

			
			<div class="method-subsection discussion-section">
				<h4 class="method-subtitle">Discussion</h4>
				<p>In certain advanced cases, you may want to customize this logic. Overriding this method allows you to receive all
three parameters and do the computation yourself.</p><div class="warning"><p><strong>Warning:</strong> Overriding this method should be done VERY rarely.</p></div>
			</div>
			

			

			

			
			<div class="method-subsection declared-in-section">
				<h4 class="method-subtitle">Declared In</h4>
				<p><code class="declared-in-ref">ASDisplayNode+Subclasses.h</code></p>
			</div>
			
			
		</div>
	</div>
</div><div class="section-method">
	<a name="//api/name/calculateSizeThatFits:" title="calculateSizeThatFits:"></a>
	<h3 class="method-title"><code><a href="#//api/name/calculateSizeThatFits:">&ndash;&nbsp;calculateSizeThatFits:</a></code>
</h3>

	<div class="method-info">
		<div class="pointy-thing"></div>

		<div class="method-info-container">
			
			
			<div class="method-subsection brief-description">
				<p>Return the calculated size.</p>
			</div>
			
		    

			<div class="method-subsection method-declaration"><code>- (CGSize)calculateSizeThatFits:(CGSize)<em>constrainedSize</em></code></div>

		    
			
			<div class="method-subsection arguments-section parameters">
				<h4 class="method-subtitle parameter-title">Parameters</h4>
				<table class="argument-def parameter-def">
				
					<tr>
						<th scope="row" class="argument-name"><code>constrainedSize</code></th>
						<td><p>The maximum size the receiver should fit in.</p></td>
					</tr>
				
				</table>
			</div>
			

			

			

			
			<div class="method-subsection discussion-section">
				<h4 class="method-subtitle">Discussion</h4>
				<p>Subclasses that override should expect this method to be called on a non-main thread. The returned size
is wrapped in an ASLayout and cached for quick access during -layout. Other expensive work that needs to
be done before display can be performed here, and using ivars to cache any valuable intermediate results is
encouraged.</p><div class="note"><p><strong>Note:</strong> Subclasses that override are committed to manual layout. Therefore, -layout: must be overriden to layout all subnodes or subviews.</p></div><div class="note"><p><strong>Note:</strong> This method should not be called directly outside of ASDisplayNode; use -layoutThatFits: or layoutThatFits:parentSize: instead.</p></div>
			</div>
			

			

			

			
			<div class="method-subsection declared-in-section">
				<h4 class="method-subtitle">Declared In</h4>
				<p><code class="declared-in-ref">ASDisplayNode+Subclasses.h</code></p>
			</div>
			
			
		</div>
	</div>
</div><div class="section-method">
	<a name="//api/name/layoutSpecThatFits:" title="layoutSpecThatFits:"></a>
	<h3 class="method-title"><code><a href="#//api/name/layoutSpecThatFits:">&ndash;&nbsp;layoutSpecThatFits:</a></code>
</h3>

	<div class="method-info">
		<div class="pointy-thing"></div>

		<div class="method-info-container">
			
			
			<div class="method-subsection brief-description">
				<p>Return a layout spec that describes the layout of the receiver and its children.</p>
			</div>
			
		    

			<div class="method-subsection method-declaration"><code>- (ASLayoutSpec *)layoutSpecThatFits:(ASSizeRange)<em>constrainedSize</em></code></div>

		    
			
			<div class="method-subsection arguments-section parameters">
				<h4 class="method-subtitle parameter-title">Parameters</h4>
				<table class="argument-def parameter-def">
				
					<tr>
						<th scope="row" class="argument-name"><code>constrainedSize</code></th>
						<td><p>The minimum and maximum sizes the receiver should fit in.</p></td>
					</tr>
				
				</table>
			</div>
			

			

			

			
			<div class="method-subsection discussion-section">
				<h4 class="method-subtitle">Discussion</h4>
				<p>Subclasses that override should expect this method to be called on a non-main thread. The returned layout spec
is used to calculate an ASLayout and cached by ASDisplayNode for quick access during -layout. Other expensive work that needs to
be done before display can be performed here, and using ivars to cache any valuable intermediate results is
encouraged.</p><div class="note"><p><strong>Note:</strong> This method should not be called directly outside of ASDisplayNode; use -measure: or -calculatedLayout instead.</p></div><div class="warning"><p><strong>Warning:</strong> Subclasses that implement -layoutSpecThatFits: must not use .layoutSpecBlock. Doing so will trigger an
exception. A future version of the framework may support using both, calling them serially, with the .layoutSpecBlock
superseding any values set by the method override.</p></div>
			</div>
			

			

			

			
			<div class="method-subsection declared-in-section">
				<h4 class="method-subtitle">Declared In</h4>
				<p><code class="declared-in-ref">ASDisplayNode+Subclasses.h</code></p>
			</div>
			
			
		</div>
	</div>
</div><div class="section-method">
	<a name="//api/name/invalidateCalculatedLayout" title="invalidateCalculatedLayout"></a>
	<h3 class="method-title"><code><a href="#//api/name/invalidateCalculatedLayout">&ndash;&nbsp;invalidateCalculatedLayout</a></code>
</h3>

	<div class="method-info">
		<div class="pointy-thing"></div>

		<div class="method-info-container">
			
			
			<div class="method-subsection brief-description">
				<p>Invalidate previously measured and cached layout.</p>
			</div>
			
		    

			<div class="method-subsection method-declaration"><code>- (void)invalidateCalculatedLayout</code></div>

		    
			

			

			

			
			<div class="method-subsection discussion-section">
				<h4 class="method-subtitle">Discussion</h4>
				<p>Subclasses should call this method to invalidate the previously measured and cached layout for the display
node, when the contents of the node change in such a way as to require measuring it again.</p>
			</div>
			

			

			

			
			<div class="method-subsection declared-in-section">
				<h4 class="method-subtitle">Declared In</h4>
				<p><code class="declared-in-ref">ASDisplayNode+Subclasses.h</code></p>
			</div>
			
			
		</div>
	</div>
</div>
						</div>
						

						<a title="Drawing" name="task_Drawing"></a>
						<h2 class="task-title">Drawing</h2>

						<div class="task-list">
							<div class="section-method">
	<a name="//api/name/drawRect:withParameters:isCancelled:isRasterizing:" title="drawRect:withParameters:isCancelled:isRasterizing:"></a>
	<h3 class="method-title"><code><a href="#//api/name/drawRect:withParameters:isCancelled:isRasterizing:">+&nbsp;drawRect:withParameters:isCancelled:isRasterizing:</a></code>
</h3>

	<div class="method-info">
		<div class="pointy-thing"></div>

		<div class="method-info-container">
			
			
			<div class="method-subsection brief-description">
				<p>@summary Delegate method to draw layer contents into a CGBitmapContext. The current UIGraphics context will be set
to an appropriate context.</p>
			</div>
			
		    

			<div class="method-subsection method-declaration"><code>+ (void)drawRect:(CGRect)<em>bounds</em> withParameters:(nullable id&lt;NSObject&gt;)<em>parameters</em> isCancelled:(asdisplaynode_iscancelled_block_t)<em>isCancelledBlock</em> isRasterizing:(BOOL)<em>isRasterizing</em></code></div>

		    
			
			<div class="method-subsection arguments-section parameters">
				<h4 class="method-subtitle parameter-title">Parameters</h4>
				<table class="argument-def parameter-def">
				
					<tr>
						<th scope="row" class="argument-name"><code>bounds</code></th>
						<td><p>Region to draw in.</p></td>
					</tr>
				
					<tr>
						<th scope="row" class="argument-name"><code>parameters</code></th>
						<td><p>An object describing all of the properties you need to draw. Return this from
-drawParametersForAsyncLayer:</p></td>
					</tr>
				
					<tr>
						<th scope="row" class="argument-name"><code>isCancelledBlock</code></th>
						<td><p>Execute this block to check whether the current drawing operation has been cancelled to avoid
unnecessary work. A return value of YES means cancel drawing and return.</p></td>
					</tr>
				
					<tr>
						<th scope="row" class="argument-name"><code>isRasterizing</code></th>
						<td><p>YES if the layer is being rasterized into another layer, in which case drawRect: probably wants
to avoid doing things like filling its bounds with a zero-alpha color to clear the backing store.</p></td>
					</tr>
				
				</table>
			</div>
			

			

			

			
			<div class="method-subsection discussion-section">
				<h4 class="method-subtitle">Discussion</h4>
				<div class="note"><p><strong>Note:</strong> Called on the display queue and/or main queue (MUST BE THREAD SAFE)</p></div>
			</div>
			

			

			

			
			<div class="method-subsection declared-in-section">
				<h4 class="method-subtitle">Declared In</h4>
				<p><code class="declared-in-ref">ASDisplayNode+Subclasses.h</code></p>
			</div>
			
			
		</div>
	</div>
</div><div class="section-method">
	<a name="//api/name/displayWithParameters:isCancelled:" title="displayWithParameters:isCancelled:"></a>
	<h3 class="method-title"><code><a href="#//api/name/displayWithParameters:isCancelled:">+&nbsp;displayWithParameters:isCancelled:</a></code>
</h3>

	<div class="method-info">
		<div class="pointy-thing"></div>

		<div class="method-info-container">
			
			
			<div class="method-subsection brief-description">
				<p>@summary Delegate override to provide new layer contents as a UIImage.</p>
			</div>
			
		    

			<div class="method-subsection method-declaration"><code>+ (nullable UIImage *)displayWithParameters:(nullable id&lt;NSObject&gt;)<em>parameters</em> isCancelled:(asdisplaynode_iscancelled_block_t)<em>isCancelledBlock</em></code></div>

		    
			
			<div class="method-subsection arguments-section parameters">
				<h4 class="method-subtitle parameter-title">Parameters</h4>
				<table class="argument-def parameter-def">
				
					<tr>
						<th scope="row" class="argument-name"><code>parameters</code></th>
						<td><p>An object describing all of the properties you need to draw. Return this from
-drawParametersForAsyncLayer:</p></td>
					</tr>
				
					<tr>
						<th scope="row" class="argument-name"><code>isCancelledBlock</code></th>
						<td><p>Execute this block to check whether the current drawing operation has been cancelled to avoid
unnecessary work. A return value of YES means cancel drawing and return.</p></td>
					</tr>
				
				</table>
			</div>
			

			
			<div class="method-subsection return">
				<h4 class="method-subtitle parameter-title">Return Value</h4>
				<p>A UIImage with contents that are ready to display on the main thread. Make sure that the image is already
decoded before returning it here.</p>
			</div>
			

			

			
			<div class="method-subsection discussion-section">
				<h4 class="method-subtitle">Discussion</h4>
				<div class="note"><p><strong>Note:</strong> Called on the display queue and/or main queue (MUST BE THREAD SAFE)</p></div>
			</div>
			

			

			

			
			<div class="method-subsection declared-in-section">
				<h4 class="method-subtitle">Declared In</h4>
				<p><code class="declared-in-ref">ASDisplayNode+Subclasses.h</code></p>
			</div>
			
			
		</div>
	</div>
</div><div class="section-method">
	<a name="//api/name/drawParametersForAsyncLayer:" title="drawParametersForAsyncLayer:"></a>
	<h3 class="method-title"><code><a href="#//api/name/drawParametersForAsyncLayer:">&ndash;&nbsp;drawParametersForAsyncLayer:</a></code>
</h3>

	<div class="method-info">
		<div class="pointy-thing"></div>

		<div class="method-info-container">
			
			
			<div class="method-subsection brief-description">
				<p>Delegate override for drawParameters</p>
			</div>
			
		    

			<div class="method-subsection method-declaration"><code>- (nullable id&lt;NSObject&gt;)drawParametersForAsyncLayer:(_ASDisplayLayer *)<em>layer</em></code></div>

		    
			
			<div class="method-subsection arguments-section parameters">
				<h4 class="method-subtitle parameter-title">Parameters</h4>
				<table class="argument-def parameter-def">
				
					<tr>
						<th scope="row" class="argument-name"><code>layer</code></th>
						<td><p>The layer that will be drawn into.</p></td>
					</tr>
				
				</table>
			</div>
			

			

			

			
			<div class="method-subsection discussion-section">
				<h4 class="method-subtitle">Discussion</h4>
				<div class="note"><p><strong>Note:</strong> Called on the main thread only</p></div>
			</div>
			

			

			

			
			<div class="method-subsection declared-in-section">
				<h4 class="method-subtitle">Declared In</h4>
				<p><code class="declared-in-ref">ASDisplayNode+Subclasses.h</code></p>
			</div>
			
			
		</div>
	</div>
</div><div class="section-method">
	<a name="//api/name/displayWillStart" title="displayWillStart"></a>
	<h3 class="method-title"><code><a href="#//api/name/displayWillStart">&ndash;&nbsp;displayWillStart</a></code>
</h3>

	<div class="method-info">
		<div class="pointy-thing"></div>

		<div class="method-info-container">
			
			
			<div class="method-subsection brief-description">
				<p>Indicates that the receiver is about to display.</p>
			</div>
			
		    

			<div class="method-subsection method-declaration"><code>- (void)displayWillStart</code></div>

		    
			

			

			

			
			<div class="method-subsection discussion-section">
				<h4 class="method-subtitle">Discussion</h4>
				<p>Subclasses may override this method to be notified when display (asynchronous or synchronous) is
about to begin.</p><div class="note"><p><strong>Note:</strong> Called on the main thread only</p></div>
			</div>
			

			

			

			
			<div class="method-subsection declared-in-section">
				<h4 class="method-subtitle">Declared In</h4>
				<p><code class="declared-in-ref">ASDisplayNode+Subclasses.h</code></p>
			</div>
			
			
		</div>
	</div>
</div><div class="section-method">
	<a name="//api/name/displayDidFinish" title="displayDidFinish"></a>
	<h3 class="method-title"><code><a href="#//api/name/displayDidFinish">&ndash;&nbsp;displayDidFinish</a></code>
</h3>

	<div class="method-info">
		<div class="pointy-thing"></div>

		<div class="method-info-container">
			
			
			<div class="method-subsection brief-description">
				<p>Indicates that the receiver has finished displaying.</p>
			</div>
			
		    

			<div class="method-subsection method-declaration"><code>- (void)displayDidFinish</code></div>

		    
			

			

			

			
			<div class="method-subsection discussion-section">
				<h4 class="method-subtitle">Discussion</h4>
				<p>Subclasses may override this method to be notified when display (asynchronous or synchronous) has
completed.</p><div class="note"><p><strong>Note:</strong> Called on the main thread only</p></div>
			</div>
			

			

			

			
			<div class="method-subsection declared-in-section">
				<h4 class="method-subtitle">Declared In</h4>
				<p><code class="declared-in-ref">ASDisplayNode+Subclasses.h</code></p>
			</div>
			
			
		</div>
	</div>
</div>
						</div>
						

						<a title="Observing node-related changes" name="task_Observing node-related changes"></a>
						<h2 class="task-title">Observing node-related changes</h2>

						<div class="task-list">
							<div class="section-method">
	<a name="//api/name/interfaceStateDidChange:fromState:" title="interfaceStateDidChange:fromState:"></a>
	<h3 class="method-title"><code><a href="#//api/name/interfaceStateDidChange:fromState:">&ndash;&nbsp;interfaceStateDidChange:fromState:</a></code>
</h3>

	<div class="method-info">
		<div class="pointy-thing"></div>

		<div class="method-info-container">
			
			
			<div class="method-subsection brief-description">
				<p>Called whenever any bit in the ASInterfaceState bitfield is changed.</p>
			</div>
			
		    

			<div class="method-subsection method-declaration"><code>- (void)interfaceStateDidChange:(ASInterfaceState)<em>newState</em> fromState:(ASInterfaceState)<em>oldState</em></code></div>

		    
			

			

			

			
			<div class="method-subsection discussion-section">
				<h4 class="method-subtitle">Discussion</h4>
				<p>Subclasses may use this to monitor when they become visible, should free cached data, and much more.</p>
			</div>
			

			

			
			<div class="method-subsection see-also-section">
				<h4 class="method-subtitle">See Also</h4>
				<ul>
					
					<li><code><p><a href="../Constants/ASInterfaceState.html">ASInterfaceState</a></p></code></li>
					
				</ul>
			</div>
			

			
			<div class="method-subsection declared-in-section">
				<h4 class="method-subtitle">Declared In</h4>
				<p><code class="declared-in-ref">ASDisplayNode+Subclasses.h</code></p>
			</div>
			
			
		</div>
	</div>
</div><div class="section-method">
	<a name="//api/name/didEnterVisibleState" title="didEnterVisibleState"></a>
	<h3 class="method-title"><code><a href="#//api/name/didEnterVisibleState">&ndash;&nbsp;didEnterVisibleState</a></code>
</h3>

	<div class="method-info">
		<div class="pointy-thing"></div>

		<div class="method-info-container">
			
			
			<div class="method-subsection brief-description">
				<p>Called whenever the node becomes visible.</p>
			</div>
			
		    

			<div class="method-subsection method-declaration"><code>- (void)didEnterVisibleState</code></div>

		    
			

			

			

			
			<div class="method-subsection discussion-section">
				<h4 class="method-subtitle">Discussion</h4>
				<p>Subclasses may use this to monitor when they become visible.</p><div class="note"><p><strong>Note:</strong> This method is guaranteed to be called on main.</p></div>
			</div>
			

			

			

			
			<div class="method-subsection declared-in-section">
				<h4 class="method-subtitle">Declared In</h4>
				<p><code class="declared-in-ref">ASDisplayNode+Subclasses.h</code></p>
			</div>
			
			
		</div>
	</div>
</div><div class="section-method">
	<a name="//api/name/didExitVisibleState" title="didExitVisibleState"></a>
	<h3 class="method-title"><code><a href="#//api/name/didExitVisibleState">&ndash;&nbsp;didExitVisibleState</a></code>
</h3>

	<div class="method-info">
		<div class="pointy-thing"></div>

		<div class="method-info-container">
			
			
			<div class="method-subsection brief-description">
				<p>Called whenever the node is no longer visible.</p>
			</div>
			
		    

			<div class="method-subsection method-declaration"><code>- (void)didExitVisibleState</code></div>

		    
			

			

			

			
			<div class="method-subsection discussion-section">
				<h4 class="method-subtitle">Discussion</h4>
				<p>Subclasses may use this to monitor when they are no longer visible.</p><div class="note"><p><strong>Note:</strong> This method is guaranteed to be called on main.</p></div>
			</div>
			

			

			

			
			<div class="method-subsection declared-in-section">
				<h4 class="method-subtitle">Declared In</h4>
				<p><code class="declared-in-ref">ASDisplayNode+Subclasses.h</code></p>
			</div>
			
			
		</div>
	</div>
</div><div class="section-method">
	<a name="//api/name/didEnterDisplayState" title="didEnterDisplayState"></a>
	<h3 class="method-title"><code><a href="#//api/name/didEnterDisplayState">&ndash;&nbsp;didEnterDisplayState</a></code>
</h3>

	<div class="method-info">
		<div class="pointy-thing"></div>

		<div class="method-info-container">
			
			
			<div class="method-subsection brief-description">
				<p>Called whenever the the node has entered the display state.</p>
			</div>
			
		    

			<div class="method-subsection method-declaration"><code>- (void)didEnterDisplayState</code></div>

		    
			

			

			

			
			<div class="method-subsection discussion-section">
				<h4 class="method-subtitle">Discussion</h4>
				<p>Subclasses may use this to monitor when a node should be rendering its content.</p><div class="note"><p><strong>Note:</strong> This method is guaranteed to be called on main.</p></div>
			</div>
			

			

			

			
			<div class="method-subsection declared-in-section">
				<h4 class="method-subtitle">Declared In</h4>
				<p><code class="declared-in-ref">ASDisplayNode+Subclasses.h</code></p>
			</div>
			
			
		</div>
	</div>
</div><div class="section-method">
	<a name="//api/name/didExitDisplayState" title="didExitDisplayState"></a>
	<h3 class="method-title"><code><a href="#//api/name/didExitDisplayState">&ndash;&nbsp;didExitDisplayState</a></code>
</h3>

	<div class="method-info">
		<div class="pointy-thing"></div>

		<div class="method-info-container">
			
			
			<div class="method-subsection brief-description">
				<p>Called whenever the the node has exited the display state.</p>
			</div>
			
		    

			<div class="method-subsection method-declaration"><code>- (void)didExitDisplayState</code></div>

		    
			

			

			

			
			<div class="method-subsection discussion-section">
				<h4 class="method-subtitle">Discussion</h4>
				<p>Subclasses may use this to monitor when a node should no longer be rendering its content.</p><div class="note"><p><strong>Note:</strong> This method is guaranteed to be called on main.</p></div>
			</div>
			

			

			

			
			<div class="method-subsection declared-in-section">
				<h4 class="method-subtitle">Declared In</h4>
				<p><code class="declared-in-ref">ASDisplayNode+Subclasses.h</code></p>
			</div>
			
			
		</div>
	</div>
</div><div class="section-method">
	<a name="//api/name/didEnterPreloadState" title="didEnterPreloadState"></a>
	<h3 class="method-title"><code><a href="#//api/name/didEnterPreloadState">&ndash;&nbsp;didEnterPreloadState</a></code>
</h3>

	<div class="method-info">
		<div class="pointy-thing"></div>

		<div class="method-info-container">
			
			
			<div class="method-subsection brief-description">
				<p>Called whenever the the node has entered the preload state.</p>
			</div>
			
		    

			<div class="method-subsection method-declaration"><code>- (void)didEnterPreloadState</code></div>

		    
			

			

			

			
			<div class="method-subsection discussion-section">
				<h4 class="method-subtitle">Discussion</h4>
				<p>Subclasses may use this to monitor data for a node should be preloaded, either from a local or remote source.</p><div class="note"><p><strong>Note:</strong> This method is guaranteed to be called on main.</p></div>
			</div>
			

			

			

			
			<div class="method-subsection declared-in-section">
				<h4 class="method-subtitle">Declared In</h4>
				<p><code class="declared-in-ref">ASDisplayNode+Subclasses.h</code></p>
			</div>
			
			
		</div>
	</div>
</div><div class="section-method">
	<a name="//api/name/didExitPreloadState" title="didExitPreloadState"></a>
	<h3 class="method-title"><code><a href="#//api/name/didExitPreloadState">&ndash;&nbsp;didExitPreloadState</a></code>
</h3>

	<div class="method-info">
		<div class="pointy-thing"></div>

		<div class="method-info-container">
			
			
			<div class="method-subsection brief-description">
				<p>Called whenever the the node has exited the preload state.</p>
			</div>
			
		    

			<div class="method-subsection method-declaration"><code>- (void)didExitPreloadState</code></div>

		    
			

			

			

			
			<div class="method-subsection discussion-section">
				<h4 class="method-subtitle">Discussion</h4>
				<p>Subclasses may use this to monitor whether preloading data for a node should be canceled.</p><div class="note"><p><strong>Note:</strong> This method is guaranteed to be called on main.</p></div>
			</div>
			

			

			

			
			<div class="method-subsection declared-in-section">
				<h4 class="method-subtitle">Declared In</h4>
				<p><code class="declared-in-ref">ASDisplayNode+Subclasses.h</code></p>
			</div>
			
			
		</div>
	</div>
</div><div class="section-method">
	<a name="//api/name/willEnterHierarchy" title="willEnterHierarchy"></a>
	<h3 class="method-title"><code><a href="#//api/name/willEnterHierarchy">&ndash;&nbsp;willEnterHierarchy</a></code>
</h3>

	<div class="method-info">
		<div class="pointy-thing"></div>

		<div class="method-info-container">
			
			
			<div class="method-subsection brief-description">
				<p>Called just before the view is added to a window.</p>
			</div>
			
		    

			<div class="method-subsection method-declaration"><code>- (void)willEnterHierarchy</code></div>

		    
			

			

			

			

			

			

			
			<div class="method-subsection declared-in-section">
				<h4 class="method-subtitle">Declared In</h4>
				<p><code class="declared-in-ref">ASDisplayNode+Subclasses.h</code></p>
			</div>
			
			
		</div>
	</div>
</div><div class="section-method">
	<a name="//api/name/didExitHierarchy" title="didExitHierarchy"></a>
	<h3 class="method-title"><code><a href="#//api/name/didExitHierarchy">&ndash;&nbsp;didExitHierarchy</a></code>
</h3>

	<div class="method-info">
		<div class="pointy-thing"></div>

		<div class="method-info-container">
			
			
			<div class="method-subsection brief-description">
				<p>Called after the view is removed from the window.</p>
			</div>
			
		    

			<div class="method-subsection method-declaration"><code>- (void)didExitHierarchy</code></div>

		    
			

			

			

			

			

			

			
			<div class="method-subsection declared-in-section">
				<h4 class="method-subtitle">Declared In</h4>
				<p><code class="declared-in-ref">ASDisplayNode+Subclasses.h</code></p>
			</div>
			
			
		</div>
	</div>
</div><div class="section-method">
	<a name="//api/name/inHierarchy" title="inHierarchy"></a>
	<h3 class="method-title"><code><a href="#//api/name/inHierarchy">&nbsp;&nbsp;inHierarchy</a></code>
</h3>

	<div class="method-info">
		<div class="pointy-thing"></div>

		<div class="method-info-container">
			
			
			<div class="method-subsection brief-description">
				<p>Whether the view or layer of this display node is currently in a window</p>
			</div>
			
		    

			<div class="method-subsection method-declaration"><code>@property (nonatomic, readonly, assign, getter=isInHierarchy) BOOL inHierarchy</code></div>

		    
			

			

			

			

			

			

			
			<div class="method-subsection declared-in-section">
				<h4 class="method-subtitle">Declared In</h4>
				<p><code class="declared-in-ref">ASDisplayNode+Subclasses.h</code></p>
			</div>
			
			
		</div>
	</div>
</div><div class="section-method">
	<a name="//api/name/fetchData" title="fetchData"></a>
	<h3 class="method-title"><code><a href="#//api/name/fetchData">&ndash;&nbsp;fetchData</a></code>
</h3>

	<div class="method-info">
		<div class="pointy-thing"></div>

		<div class="method-info-container">
			
			
			<div class="method-subsection brief-description">
				<p>Indicates that the node should fetch any external data, such as images.</p>
			</div>
			
		    

			<div class="method-subsection method-declaration"><code>- (void)fetchData</code></div>

		    
			

			

			

			
			<div class="method-subsection discussion-section">
				<h4 class="method-subtitle">Discussion</h4>
				<p>Subclasses may override this method to be notified when they should begin to fetch data. Fetching
should be done asynchronously. The node is also responsible for managing the memory of any data.
The data may be remote and accessed via the network, but could also be a local database query.</p>
			</div>
			

			

			

			
			<div class="method-subsection declared-in-section">
				<h4 class="method-subtitle">Declared In</h4>
				<p><code class="declared-in-ref">ASDisplayNode+Subclasses.h</code></p>
			</div>
			
			
		</div>
	</div>
</div><div class="section-method">
	<a name="//api/name/clearFetchedData" title="clearFetchedData"></a>
	<h3 class="method-title"><code><a href="#//api/name/clearFetchedData">&ndash;&nbsp;clearFetchedData</a></code>
</h3>

	<div class="method-info">
		<div class="pointy-thing"></div>

		<div class="method-info-container">
			
			
			<div class="method-subsection brief-description">
				<p>Provides an opportunity to clear any fetched data (e.g. remote / network or database-queried) on the current node.</p>
			</div>
			
		    

			<div class="method-subsection method-declaration"><code>- (void)clearFetchedData</code></div>

		    
			

			

			

			
			<div class="method-subsection discussion-section">
				<h4 class="method-subtitle">Discussion</h4>
				<p>This will not clear data recursively for all subnodes. Either call -recursivelyClearFetchedData or
selectively clear fetched data.</p>
			</div>
			

			

			

			
			<div class="method-subsection declared-in-section">
				<h4 class="method-subtitle">Declared In</h4>
				<p><code class="declared-in-ref">ASDisplayNode+Subclasses.h</code></p>
			</div>
			
			
		</div>
	</div>
</div><div class="section-method">
	<a name="//api/name/clearContents" title="clearContents"></a>
	<h3 class="method-title"><code><a href="#//api/name/clearContents">&ndash;&nbsp;clearContents</a></code>
</h3>

	<div class="method-info">
		<div class="pointy-thing"></div>

		<div class="method-info-container">
			
			
			<div class="method-subsection brief-description">
				<p>Provides an opportunity to clear backing store and other memory-intensive intermediates, such as text layout managers
on the current node.</p>
			</div>
			
		    

			<div class="method-subsection method-declaration"><code>- (void)clearContents</code></div>

		    
			

			

			

			
			<div class="method-subsection discussion-section">
				<h4 class="method-subtitle">Discussion</h4>
				<p>Called by -recursivelyClearContents. Base class implements self.contents = nil, clearing any backing
store, for asynchronous regeneration when needed.</p>
			</div>
			

			

			

			
			<div class="method-subsection declared-in-section">
				<h4 class="method-subtitle">Declared In</h4>
				<p><code class="declared-in-ref">ASDisplayNode+Subclasses.h</code></p>
			</div>
			
			
		</div>
	</div>
</div><div class="section-method">
	<a name="//api/name/subnodeDisplayWillStart:" title="subnodeDisplayWillStart:"></a>
	<h3 class="method-title"><code><a href="#//api/name/subnodeDisplayWillStart:">&ndash;&nbsp;subnodeDisplayWillStart:</a></code>
</h3>

	<div class="method-info">
		<div class="pointy-thing"></div>

		<div class="method-info-container">
			
			
			<div class="method-subsection brief-description">
				<p>Indicates that the receiver is about to display its subnodes. This method is not called if there are no
subnodes present.</p>
			</div>
			
		    

			<div class="method-subsection method-declaration"><code>- (void)subnodeDisplayWillStart:(ASDisplayNode *)<em>subnode</em></code></div>

		    
			
			<div class="method-subsection arguments-section parameters">
				<h4 class="method-subtitle parameter-title">Parameters</h4>
				<table class="argument-def parameter-def">
				
					<tr>
						<th scope="row" class="argument-name"><code>subnode</code></th>
						<td><p>The subnode of which display is about to begin.</p></td>
					</tr>
				
				</table>
			</div>
			

			

			

			
			<div class="method-subsection discussion-section">
				<h4 class="method-subtitle">Discussion</h4>
				<p>Subclasses may override this method to be notified when subnode display (asynchronous or synchronous) is
about to begin.</p>
			</div>
			

			

			

			
			<div class="method-subsection declared-in-section">
				<h4 class="method-subtitle">Declared In</h4>
				<p><code class="declared-in-ref">ASDisplayNode+Subclasses.h</code></p>
			</div>
			
			
		</div>
	</div>
</div><div class="section-method">
	<a name="//api/name/subnodeDisplayDidFinish:" title="subnodeDisplayDidFinish:"></a>
	<h3 class="method-title"><code><a href="#//api/name/subnodeDisplayDidFinish:">&ndash;&nbsp;subnodeDisplayDidFinish:</a></code>
</h3>

	<div class="method-info">
		<div class="pointy-thing"></div>

		<div class="method-info-container">
			
			
			<div class="method-subsection brief-description">
				<p>Indicates that the receiver is finished displaying its subnodes. This method is not called if there are
no subnodes present.</p>
			</div>
			
		    

			<div class="method-subsection method-declaration"><code>- (void)subnodeDisplayDidFinish:(ASDisplayNode *)<em>subnode</em></code></div>

		    
			
			<div class="method-subsection arguments-section parameters">
				<h4 class="method-subtitle parameter-title">Parameters</h4>
				<table class="argument-def parameter-def">
				
					<tr>
						<th scope="row" class="argument-name"><code>subnode</code></th>
						<td><p>The subnode of which display is about to completed.</p></td>
					</tr>
				
				</table>
			</div>
			

			

			

			
			<div class="method-subsection discussion-section">
				<h4 class="method-subtitle">Discussion</h4>
				<p>Subclasses may override this method to be notified when subnode display (asynchronous or synchronous) has
completed.</p>
			</div>
			

			

			

			
			<div class="method-subsection declared-in-section">
				<h4 class="method-subtitle">Declared In</h4>
				<p><code class="declared-in-ref">ASDisplayNode+Subclasses.h</code></p>
			</div>
			
			
		</div>
	</div>
</div><div class="section-method">
	<a name="//api/name/setNeedsDisplayAtScale:" title="setNeedsDisplayAtScale:"></a>
	<h3 class="method-title"><code><a href="#//api/name/setNeedsDisplayAtScale:">&ndash;&nbsp;setNeedsDisplayAtScale:</a></code>
</h3>

	<div class="method-info">
		<div class="pointy-thing"></div>

		<div class="method-info-container">
			
			
			<div class="method-subsection brief-description">
				<p>Marks the receiver&rsquo;s bounds as needing to be redrawn, with a scale value.</p>
			</div>
			
		    

			<div class="method-subsection method-declaration"><code>- (void)setNeedsDisplayAtScale:(CGFloat)<em>contentsScale</em></code></div>

		    
			
			<div class="method-subsection arguments-section parameters">
				<h4 class="method-subtitle parameter-title">Parameters</h4>
				<table class="argument-def parameter-def">
				
					<tr>
						<th scope="row" class="argument-name"><code>contentsScale</code></th>
						<td><p>The scale at which the receiver should be drawn.</p></td>
					</tr>
				
				</table>
			</div>
			

			

			

			
			<div class="method-subsection discussion-section">
				<h4 class="method-subtitle">Discussion</h4>
				<p>Subclasses should override this if they don&rsquo;t want their contentsScale changed.</p><div class="note"><p><strong>Note:</strong> This changes an internal property.
-setNeedsDisplay is also available to trigger display without changing contentsScaleForDisplay.</p></div>
			</div>
			

			

			
			<div class="method-subsection see-also-section">
				<h4 class="method-subtitle">See Also</h4>
				<ul>
					
					<li><code><p>-setNeedsDisplay, <a href="#//api/name/contentsScaleForDisplay">@property contentsScaleForDisplay</a></p></code></li>
					
				</ul>
			</div>
			

			
			<div class="method-subsection declared-in-section">
				<h4 class="method-subtitle">Declared In</h4>
				<p><code class="declared-in-ref">ASDisplayNode+Subclasses.h</code></p>
			</div>
			
			
		</div>
	</div>
</div><div class="section-method">
	<a name="//api/name/recursivelySetNeedsDisplayAtScale:" title="recursivelySetNeedsDisplayAtScale:"></a>
	<h3 class="method-title"><code><a href="#//api/name/recursivelySetNeedsDisplayAtScale:">&ndash;&nbsp;recursivelySetNeedsDisplayAtScale:</a></code>
</h3>

	<div class="method-info">
		<div class="pointy-thing"></div>

		<div class="method-info-container">
			
			
			<div class="method-subsection brief-description">
				<p>Recursively calls setNeedsDisplayAtScale: on subnodes.</p>
			</div>
			
		    

			<div class="method-subsection method-declaration"><code>- (void)recursivelySetNeedsDisplayAtScale:(CGFloat)<em>contentsScale</em></code></div>

		    
			
			<div class="method-subsection arguments-section parameters">
				<h4 class="method-subtitle parameter-title">Parameters</h4>
				<table class="argument-def parameter-def">
				
					<tr>
						<th scope="row" class="argument-name"><code>contentsScale</code></th>
						<td><p>The scale at which the receiver&rsquo;s subnode hierarchy should be drawn.</p></td>
					</tr>
				
				</table>
			</div>
			

			

			

			
			<div class="method-subsection discussion-section">
				<h4 class="method-subtitle">Discussion</h4>
				<p>Subclasses may override this if they require modifying the scale set on their child nodes.</p><div class="note"><p><strong>Note:</strong> Only the node tree is walked, not the view or layer trees.</p></div>
			</div>
			

			

			
			<div class="method-subsection see-also-section">
				<h4 class="method-subtitle">See Also</h4>
				<ul>
					
					<li><code><p><a href="#//api/name/setNeedsDisplayAtScale:">- setNeedsDisplayAtScale:</a></p></code></li>
					
					<li><code><p><a href="#//api/name/contentsScaleForDisplay">@property contentsScaleForDisplay</a></p></code></li>
					
				</ul>
			</div>
			

			
			<div class="method-subsection declared-in-section">
				<h4 class="method-subtitle">Declared In</h4>
				<p><code class="declared-in-ref">ASDisplayNode+Subclasses.h</code></p>
			</div>
			
			
		</div>
	</div>
</div><div class="section-method">
	<a name="//api/name/contentsScaleForDisplay" title="contentsScaleForDisplay"></a>
	<h3 class="method-title"><code><a href="#//api/name/contentsScaleForDisplay">&nbsp;&nbsp;contentsScaleForDisplay</a></code>
</h3>

	<div class="method-info">
		<div class="pointy-thing"></div>

		<div class="method-info-container">
			
			
			<div class="method-subsection brief-description">
				<p>The scale factor to apply to the rendering.</p>
			</div>
			
		    

			<div class="method-subsection method-declaration"><code>@property (nonatomic, assign, readonly) CGFloat contentsScaleForDisplay</code></div>

		    
			

			

			

			
			<div class="method-subsection discussion-section">
				<h4 class="method-subtitle">Discussion</h4>
				<p>Use setNeedsDisplayAtScale: to set a value and then after display, the display node will set the layer&rsquo;s
contentsScale. This is to prevent jumps when re-rasterizing at a different contentsScale.
Read this property if you need to know the future contentsScale of your layer, eg in drawParameters.</p>
			</div>
			

			

			
			<div class="method-subsection see-also-section">
				<h4 class="method-subtitle">See Also</h4>
				<ul>
					
					<li><code><p><a href="#//api/name/setNeedsDisplayAtScale:">- setNeedsDisplayAtScale:</a></p></code></li>
					
				</ul>
			</div>
			

			
			<div class="method-subsection declared-in-section">
				<h4 class="method-subtitle">Declared In</h4>
				<p><code class="declared-in-ref">ASDisplayNode+Subclasses.h</code></p>
			</div>
			
			
		</div>
	</div>
</div>
						</div>
						

						<a title="Touch handling" name="task_Touch handling"></a>
						<h2 class="task-title">Touch handling</h2>

						<div class="task-list">
							<div class="section-method">
	<a name="//api/name/touchesBegan:withEvent:" title="touchesBegan:withEvent:"></a>
	<h3 class="method-title"><code><a href="#//api/name/touchesBegan:withEvent:">&ndash;&nbsp;touchesBegan:withEvent:</a></code>
</h3>

	<div class="method-info">
		<div class="pointy-thing"></div>

		<div class="method-info-container">
			
			
			<div class="method-subsection brief-description">
				<p>Tells the node when touches began in its view.</p>
			</div>
			
		    

			<div class="method-subsection method-declaration"><code>- (void)touchesBegan:(NSSet&lt;UITouch*&gt; *)<em>touches</em> withEvent:(nullable UIEvent *)<em>event</em></code></div>

		    
			
			<div class="method-subsection arguments-section parameters">
				<h4 class="method-subtitle parameter-title">Parameters</h4>
				<table class="argument-def parameter-def">
				
					<tr>
						<th scope="row" class="argument-name"><code>touches</code></th>
						<td><p>A set of UITouch instances.</p></td>
					</tr>
				
					<tr>
						<th scope="row" class="argument-name"><code>event</code></th>
						<td><p>A UIEvent associated with the touch.</p></td>
					</tr>
				
				</table>
			</div>
			

			

			

			

			

			

			
			<div class="method-subsection declared-in-section">
				<h4 class="method-subtitle">Declared In</h4>
				<p><code class="declared-in-ref">ASDisplayNode+Subclasses.h</code></p>
			</div>
			
			
		</div>
	</div>
</div><div class="section-method">
	<a name="//api/name/touchesMoved:withEvent:" title="touchesMoved:withEvent:"></a>
	<h3 class="method-title"><code><a href="#//api/name/touchesMoved:withEvent:">&ndash;&nbsp;touchesMoved:withEvent:</a></code>
</h3>

	<div class="method-info">
		<div class="pointy-thing"></div>

		<div class="method-info-container">
			
			
			<div class="method-subsection brief-description">
				<p>Tells the node when touches moved in its view.</p>
			</div>
			
		    

			<div class="method-subsection method-declaration"><code>- (void)touchesMoved:(NSSet&lt;UITouch*&gt; *)<em>touches</em> withEvent:(nullable UIEvent *)<em>event</em></code></div>

		    
			
			<div class="method-subsection arguments-section parameters">
				<h4 class="method-subtitle parameter-title">Parameters</h4>
				<table class="argument-def parameter-def">
				
					<tr>
						<th scope="row" class="argument-name"><code>touches</code></th>
						<td><p>A set of UITouch instances.</p></td>
					</tr>
				
					<tr>
						<th scope="row" class="argument-name"><code>event</code></th>
						<td><p>A UIEvent associated with the touch.</p></td>
					</tr>
				
				</table>
			</div>
			

			

			

			

			

			

			
			<div class="method-subsection declared-in-section">
				<h4 class="method-subtitle">Declared In</h4>
				<p><code class="declared-in-ref">ASDisplayNode+Subclasses.h</code></p>
			</div>
			
			
		</div>
	</div>
</div><div class="section-method">
	<a name="//api/name/touchesEnded:withEvent:" title="touchesEnded:withEvent:"></a>
	<h3 class="method-title"><code><a href="#//api/name/touchesEnded:withEvent:">&ndash;&nbsp;touchesEnded:withEvent:</a></code>
</h3>

	<div class="method-info">
		<div class="pointy-thing"></div>

		<div class="method-info-container">
			
			
			<div class="method-subsection brief-description">
				<p>Tells the node when touches ended in its view.</p>
			</div>
			
		    

			<div class="method-subsection method-declaration"><code>- (void)touchesEnded:(NSSet&lt;UITouch*&gt; *)<em>touches</em> withEvent:(nullable UIEvent *)<em>event</em></code></div>

		    
			
			<div class="method-subsection arguments-section parameters">
				<h4 class="method-subtitle parameter-title">Parameters</h4>
				<table class="argument-def parameter-def">
				
					<tr>
						<th scope="row" class="argument-name"><code>touches</code></th>
						<td><p>A set of UITouch instances.</p></td>
					</tr>
				
					<tr>
						<th scope="row" class="argument-name"><code>event</code></th>
						<td><p>A UIEvent associated with the touch.</p></td>
					</tr>
				
				</table>
			</div>
			

			

			

			

			

			

			
			<div class="method-subsection declared-in-section">
				<h4 class="method-subtitle">Declared In</h4>
				<p><code class="declared-in-ref">ASDisplayNode+Subclasses.h</code></p>
			</div>
			
			
		</div>
	</div>
</div><div class="section-method">
	<a name="//api/name/touchesCancelled:withEvent:" title="touchesCancelled:withEvent:"></a>
	<h3 class="method-title"><code><a href="#//api/name/touchesCancelled:withEvent:">&ndash;&nbsp;touchesCancelled:withEvent:</a></code>
</h3>

	<div class="method-info">
		<div class="pointy-thing"></div>

		<div class="method-info-container">
			
			
			<div class="method-subsection brief-description">
				<p>Tells the node when touches was cancelled in its view.</p>
			</div>
			
		    

			<div class="method-subsection method-declaration"><code>- (void)touchesCancelled:(nullable NSSet&lt;UITouch*&gt; *)<em>touches</em> withEvent:(nullable UIEvent *)<em>event</em></code></div>

		    
			
			<div class="method-subsection arguments-section parameters">
				<h4 class="method-subtitle parameter-title">Parameters</h4>
				<table class="argument-def parameter-def">
				
					<tr>
						<th scope="row" class="argument-name"><code>touches</code></th>
						<td><p>A set of UITouch instances.</p></td>
					</tr>
				
					<tr>
						<th scope="row" class="argument-name"><code>event</code></th>
						<td><p>A UIEvent associated with the touch.</p></td>
					</tr>
				
				</table>
			</div>
			

			

			

			

			

			

			
			<div class="method-subsection declared-in-section">
				<h4 class="method-subtitle">Declared In</h4>
				<p><code class="declared-in-ref">ASDisplayNode+Subclasses.h</code></p>
			</div>
			
			
		</div>
	</div>
</div>
						</div>
						

						<a title="Managing Gesture Recognizers" name="task_Managing Gesture Recognizers"></a>
						<h2 class="task-title">Managing Gesture Recognizers</h2>

						<div class="task-list">
							<div class="section-method">
	<a name="//api/name/gestureRecognizerShouldBegin:" title="gestureRecognizerShouldBegin:"></a>
	<h3 class="method-title"><code><a href="#//api/name/gestureRecognizerShouldBegin:">&ndash;&nbsp;gestureRecognizerShouldBegin:</a></code>
</h3>

	<div class="method-info">
		<div class="pointy-thing"></div>

		<div class="method-info-container">
			
			
			<div class="method-subsection brief-description">
				<p>Asks the node if a gesture recognizer should continue tracking touches.</p>
			</div>
			
		    

			<div class="method-subsection method-declaration"><code>- (BOOL)gestureRecognizerShouldBegin:(UIGestureRecognizer *)<em>gestureRecognizer</em></code></div>

		    
			
			<div class="method-subsection arguments-section parameters">
				<h4 class="method-subtitle parameter-title">Parameters</h4>
				<table class="argument-def parameter-def">
				
					<tr>
						<th scope="row" class="argument-name"><code>gestureRecognizer</code></th>
						<td><p>A gesture recognizer trying to recognize a gesture.</p></td>
					</tr>
				
				</table>
			</div>
			

			

			

			

			

			

			
			<div class="method-subsection declared-in-section">
				<h4 class="method-subtitle">Declared In</h4>
				<p><code class="declared-in-ref">ASDisplayNode+Subclasses.h</code></p>
			</div>
			
			
		</div>
	</div>
</div>
						</div>
						

						<a title="Hit Testing" name="task_Hit Testing"></a>
						<h2 class="task-title">Hit Testing</h2>

						<div class="task-list">
							<div class="section-method">
	<a name="//api/name/hitTest:withEvent:" title="hitTest:withEvent:"></a>
	<h3 class="method-title"><code><a href="#//api/name/hitTest:withEvent:">&ndash;&nbsp;hitTest:withEvent:</a></code>
</h3>

	<div class="method-info">
		<div class="pointy-thing"></div>

		<div class="method-info-container">
			
			
			<div class="method-subsection brief-description">
				<p>Returns the view that contains the point.</p>
			</div>
			
		    

			<div class="method-subsection method-declaration"><code>- (nullable UIView *)hitTest:(CGPoint)<em>point</em> withEvent:(nullable UIEvent *)<em>event</em></code></div>

		    
			
			<div class="method-subsection arguments-section parameters">
				<h4 class="method-subtitle parameter-title">Parameters</h4>
				<table class="argument-def parameter-def">
				
					<tr>
						<th scope="row" class="argument-name"><code>point</code></th>
						<td><p>A point specified in the node&rsquo;s local coordinate system (bounds).</p></td>
					</tr>
				
					<tr>
						<th scope="row" class="argument-name"><code>event</code></th>
						<td><p>The event that warranted a call to this method.</p></td>
					</tr>
				
				</table>
			</div>
			

			
			<div class="method-subsection return">
				<h4 class="method-subtitle parameter-title">Return Value</h4>
				<p>Returns a UIView, not ASDisplayNode, for two reasons:
1) allows sending events to plain UIViews that don&rsquo;t have attached nodes,
2) hitTest: is never called before the views are created.</p>
			</div>
			

			

			
			<div class="method-subsection discussion-section">
				<h4 class="method-subtitle">Discussion</h4>
				<p>Override to make this node respond differently to touches: (e.g. hide touches from subviews, send all
touches to certain subviews (hit area maximizing), etc.)</p>
			</div>
			

			

			

			
			<div class="method-subsection declared-in-section">
				<h4 class="method-subtitle">Declared In</h4>
				<p><code class="declared-in-ref">ASDisplayNode+Subclasses.h</code></p>
			</div>
			
			
		</div>
	</div>
</div>
						</div>
						

						<a title="Placeholders" name="task_Placeholders"></a>
						<h2 class="task-title">Placeholders</h2>

						<div class="task-list">
							<div class="section-method">
	<a name="//api/name/placeholderImage" title="placeholderImage"></a>
	<h3 class="method-title"><code><a href="#//api/name/placeholderImage">&ndash;&nbsp;placeholderImage</a></code>
</h3>

	<div class="method-info">
		<div class="pointy-thing"></div>

		<div class="method-info-container">
			
			
			<div class="method-subsection brief-description">
				<p>Optionally provide an image to serve as the placeholder for the backing store while the contents are being
displayed.</p>
			</div>
			
		    

			<div class="method-subsection method-declaration"><code>- (nullable UIImage *)placeholderImage</code></div>

		    
			

			

			

			
			<div class="method-subsection discussion-section">
				<h4 class="method-subtitle">Discussion</h4>
				<div class="note"><p><strong>Note:</strong> Called on the display queue and/or main queue (MUST BE THREAD SAFE)</p></div>
			</div>
			

			

			

			
			<div class="method-subsection declared-in-section">
				<h4 class="method-subtitle">Declared In</h4>
				<p><code class="declared-in-ref">ASDisplayNode+Subclasses.h</code></p>
			</div>
			
			
		</div>
	</div>
</div>
						</div>
						

						<a title="Description" name="task_Description"></a>
						<h2 class="task-title">Description</h2>

						<div class="task-list">
							<div class="section-method">
	<a name="//api/name/descriptionForRecursiveDescription" title="descriptionForRecursiveDescription"></a>
	<h3 class="method-title"><code><a href="#//api/name/descriptionForRecursiveDescription">&ndash;&nbsp;descriptionForRecursiveDescription</a></code>
</h3>

	<div class="method-info">
		<div class="pointy-thing"></div>

		<div class="method-info-container">
			
			
			<div class="method-subsection brief-description">
				<p>Return a description of the node</p>
			</div>
			
		    

			<div class="method-subsection method-declaration"><code>- (NSString *)descriptionForRecursiveDescription</code></div>

		    
			

			

			

			
			<div class="method-subsection discussion-section">
				<h4 class="method-subtitle">Discussion</h4>
				<p>The function that gets called for each display node in -recursiveDescription</p>
			</div>
			

			

			

			
			<div class="method-subsection declared-in-section">
				<h4 class="method-subtitle">Declared In</h4>
				<p><code class="declared-in-ref">ASDisplayNode+Subclasses.h</code></p>
			</div>
			
			
		</div>
	</div>
</div><div class="section-method">
	<a name="//api/name/asyncTraitCollectionDidChange" title="asyncTraitCollectionDidChange"></a>
	<h3 class="method-title"><code><a href="#//api/name/asyncTraitCollectionDidChange">&ndash;&nbsp;asyncTraitCollectionDidChange</a></code>
</h3>

	<div class="method-info">
		<div class="pointy-thing"></div>

		<div class="method-info-container">
			
			
			<div class="method-subsection brief-description">
				<p>Called when the node&rsquo;s ASTraitCollection changes</p>
			</div>
			
		    

			<div class="method-subsection method-declaration"><code>- (void)asyncTraitCollectionDidChange</code></div>

		    
			

			

			

			
			<div class="method-subsection discussion-section">
				<h4 class="method-subtitle">Discussion</h4>
				<p>Subclasses can override this method to react to a trait collection change.</p>
			</div>
			

			

			

			
			<div class="method-subsection declared-in-section">
				<h4 class="method-subtitle">Declared In</h4>
				<p><code class="declared-in-ref">ASDisplayNode+Subclasses.h</code></p>
			</div>
			
			
		</div>
	</div>
</div>
						</div>
						
					</div>
					
					

                    
                    
          
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